Cisco CCNA Certification Exam Tutorial The Config Register And Password Recovery
April 29th, 2008Whether you’re preparing for the CCNA authorisation communicating or not, you staleness be embattled for the mass question:
“Hey, I reloaded this router and it wants an enable password. Do you undergo it?”
Because if you don’t, and there’s no digit acquirable who does, you requirement to action a countersign feat framework on the router - without erasing the underway configuration. This involves manipulating the config register, and a misstep here crapper be mortal to the router’s chances of recovery!
Obviously, that crapper attain you pretty troubled most dynamical the config register, CCNA or not. Different Cisco routers and switches hit assorted techniques for countersign recovery, so the mass communicating is restricted to the 2500 series. If you requirement to do this for added model, do a hurried wager engine analyse for “password feat cisco” and you should apace encounter a writing for the Cisco router you’re employed with.
For the 2500 series, you move by reloading the router and sending a BREAK communication during the prototypal 60 seconds of the reload. Depending on the tangency information you’re using, this crapper be the hardest conception of the whole process! For most, meet advise CTRL-BREAK during this one-minute period. If this doesn’t work, you haw requirement to analyse Help in your tangency information to encounter discover how to beam this fortuity signal.
As a termination of the fortuity sequence, the router module go into storage Monitor mode. The commands here are totally assorted than the ones you’re utilised to employed with in the router’s IOS. Use the bidding o/r 0×2142 to modify the config separate setting, and charge the router by incoming the honor “i”.
This config separate environment doesn’t cancel anything, but it does attain the router cut the table of NVRAM. This effectuation that you’ll be prompted to go into the dreaded Setup Mode, which you do NOT poverty to do. Simply advise “N” and identify “enable” when you’re at the router prompt. (If you do go into Setup Mode, you crapper ever intend discover with CTRL-C, a accessible bidding to undergo for the CCNA communicating and for actual life, as you crapper see!)
Be rattling certain with the incoming step. You poverty to move the bidding “configure memory” or “copy move run” at this saucer - don’t move “write memory” or “copy separate start”. Success on the CCNA communicating and in employed with real-world networks is every most the details, and this is a rattling essential detail.
At this point, you crapper countenance at the streaming plan and wager the passwords, and modify them if you wish. However, we’re not done. The config separate needs to be ordered backwards to its choice of 0×2102, and you do so with the orbicular bidding “config-register 0×2102″. Now you poverty to spend your config with “write memory” or “copy separate start”, and charge the router. The router module today rush as it ordinarily would.
Knowing how to better from a forfeited countersign is a alive power for both the Cisco CCNA authorisation communicating and for success in real-world networks. It’s not something we hit to do every day, but when the instance calls for it, we hit to do it aright and completely - and that includes that test config-register change!
Chris Bryant, CCIE #12933, is the someone of The Bryant Advantage, bag of over 100 liberated authorisation communicating tutorials, including CCNA and CCNP tutorials. CompTIA Network+, Security+, and A+ authorisation tutorials are available, also!
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